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Close up stereo-photography

Summary of methods for close-up stereo photography

Examples of close-up stereo photography

Wattie's practical, no maths method

Depth of field in Macro Photography

Small f number and diffraction

Mathematics of the

macro stereo base and

window


Second edition

EDITION 2: Macro photography with toe-in cameras

More modern methods for wide screen stereo, perfect roundness and stacking.

Close-up photography moves to high magnification macrophotography

 

Methods for close up stereoscopy include:

  1. Move the camera sideways then converge. Preferably the camera axes are symmetrical about the mid line between the two camera positions and convergence is kept to the minimum necessary for the desired horizontal field of view. (Keystone distortion.) Any of the various methods where a single camera is moved only work on static subjects. They are useless for live insects.
  2. Use two cameras and converge (keystone distortion). Described by Rob Crockett.
  3. Two cameras and do not converge: this does not allow true macro photography because the stereo base is too big.
  4. Move the camera sideways but do not converge. Cut the frames later for correct window effect. This only works when an object is in square or portrait format, but is photographed with a camera in landscape format. 
    (Explanation for this paradox, along with a bunch of formulae,  here
  5. Construct a sliding table for the camera, (with stops to allow various convergences, if you insist on converging).
  6. Use the parallelogram rapid shift mechanism but put shims under it to reduce the stereo shift.
  7. Set up a pivot under the object, connected by a bar to the camera, which then rapidly rotates its angle of view while still aimed and focused correctly. To reduce key stone effect, have the pivot behind the object and re-mask the stereo pair.
  8. Rotate the object centred on a turn-table and keep the camera still. This does not work well if you have a background which is not rotating. The lights should rotate with the object or retinal rivalry will occur with the shadows. Use a plain paper or black background. (keystone distortion)
  9. Rotate the camera and re-mask the stereo pair to a smaller format. (keystone distortion).
  10. Slide the lens sideways and take another picture (requires a shift lens). This does not have keystone distortion.
  11. *Use a Nimslo lenticular stereo camera. It takes four pictures. The inner two have a small separation, which is useful for macro work. It will not focus close unless a pair of matched supplementary lenses are used (e.g. 1 to 3 diopters). There is no toe-in and so re-masking is needed for correct virtual stereo window (which is a good thing).
  12. *A 4 in one ID portrait lens (e.g. Nikon) with close up supplementary lenses - a similar concept to the Nimslo camera.
  13. *Remove the camera lens and use two small lenses on an extension tube split by a septum. Rex Julian in Cambridge, New Zealand, has made this system. There is a {commercial version} by Hugo de Wijs, made in Holland and capable of spectacular 3d insect pictures. It is used on SLR cameras with  T adaptor. {Technical details here)  It works at up to f90, for maximum depth of field and so  the image is too dim for an SLR viewing screen. It is aimed and focussed by putting the subject between two rods - which in my experience (using a mono system) insects are not very tolerant of. A reflector is built in to prevent deep shadows when using on-camera flash, which is essential for insect work. A different version is purchased for different magnifications. The superb macro stereo books by Mark Blum may use this method, I suspect, although in the prefaces he does not clearly say how he produces the amazing 3D fish and insect pictures.
  14. *{ Stereo Wirgin:} two small lenses in front of the main camera lens. A commercial version, no longer made, is the Macro Realist.
  15. Single mirror stereo system
  16. *Stereo Realist Macro attachment {examples}
  17. *Another sophisticated { twin lens attachment } is available for a single camera, including its lens. This works for video and still cameras which may not have interchangeable lenses, but has to be manufactured separately for each system. The macro version has lens separation reduced, from over 90mm for the standard version and is equipped with a convergence device for adjusting the stereo window. The result is an  over and under stereo pair, properly windowed, on one film frame. I suggested a friend should buy this for video macro stereo, but the huge price in New Zealand dollars put it out of our range! There is even a tiny version for real time, rigid, endoscopic stereoscopy.
  18. *RBT camera {stereo adaptor} { Review } { Photo of RBT Macro in action. )
  19. *Use a stereo adaptor with 4 mirrors (or prisms) ("Reverse Cazes viewer technique").
  20. *Set up two surface silvered mirrors at a small angle and aim the camera at the junction (a bit clumsy for close-ups in the field, since the camera gets tied up in the foliage). First used in Russia in 1938, as far as I can tell, but based on Theodore Brown's system for standard stereo photography with one camera. There is a commercial version with bells and whistles.
  21. *{Steve Body} has developed a much better version of the two mirror set-up by adding a third mirror. This keeps the camera away from the subject. The results he gets on insects are very impressive. The system is suitable for a single digital camera and works perfectly with a flash. The stereo pair are recorded side by side on one image frame, as is true for all beam splitters, and should work for stereo video.
  22. *Set up two mirrors (or 45 degree prisms) at 90 degrees and photograph from each side.
    {Lovely insects from Japan}
  23. *One camera looks straight ahead through a half silvered mirror (from Edmonds Scientific). The second shoots the half reflection from 90 degrees to the side. By sliding the side camera forwards and back, the virtual stereo window can be moved. The half silvered mirror loses one stop of light, which is no great problem when using close up flash. {John Hart} has clear photographs and diagrams of this rig.
  24. Use a scanner and move the object from left to right side of the scanner for the two views: {scanner optics provides the stereo shift.} { - Another version}
  25. *Use a lens with two stops in it and a beam splitter behind the lens ("Nil Melior Stereo Macro" camera designed and constructed by Jac. Ferwerda.) The RBT adaptor uses a similar beam splitter but keeps the two camera lenses as well.
  26. *Two variable spacing lenses on a lens board for a technical camera: "Baby Bertha 2" stereo camera designed and built by M.P. Whitehouse. I have never seen it, but this seems rather like the Hugo de Wijs system built for a big camera.
  27. *Use a stereo microscope and two cameras. 
  28. For an example using just one microscope and filtered light, see the fly and other tiny creatures in 3D by {van Egmond}. He uses a red and a cyan anaglyph filter, butted together, in the below stage condensor. This way he gets an anaglyph stereo in just one step.
  29. Depth of field is a problem in microscopy, solved by an astronomical program: {AstroStack}.
     {John  Hart} gives extensive advice on how to use stacking programs and even Photoshop to increase depth of field in macro photography. 
  30. {CombineZ} is a sophisticated stacking program by Alan Hadley from England. Some excellent extreme magnification insect photographs are worth surfing across to see. (Not in stereo, unfortunately)
    {James Tozour} has used Combine Z for macro stereo of minerals. 
    One of {Alan Hadley's  set ups} uses web cams as if they were film holders. He removes the microscope eye-piece and cuts off the the TV camera lens, so the microscope objective projects directly onto the web cam CD chip. Resolution suffers a bit from the small number of pixels in a web cam. Somebody is going to cut the lens off a 4 megapixel digital camera one day and the result should be spectacular.
  31. Stereo microscopy by tilting the subject is commonly used. An example using the USB QX3 "toy" microscope is given {here.} (Intel are no longer making this instrument, although a similar device is available). Since the lights do not tilt, reflections can occur in just one of the stereo pairs and produce retinal rivalry. But that happens when a stereo microscope is used visually too. Microscopists do not seem to mind, because a little rivalry is better than not seeing in stereo.
  32. * No-Mir3d Method of Dr. Imre Zsolnai-Nagy
    Hello dear friends!
    Please listen me a little bit, I want share my new one camera without mirror stereo method.
    Perhaps I'm not the first person who made similar anaglyphs, but on the Internet, in the 3D world it does not exist.
    The method is very simple and similar to the QDOS system, but in the same time is TOTALLY different.
    The QDOS does not have stereo base, for this produces ONLY pseudoanaglyphs, without depth of field.
    The No-Mir3D system HAS the stereo base and produces real 3d anaglyphs.
    (The name: No-Mir3D is from me...No-Mirrors 3D...:-)) )
    The method is visible on the { attachment } and I think it is very comprehensible!!!
    So: we must cover the lens and we must do 2 little holes. The holes must be covered with red and cyan filters.
    In this case you will have a ONE SHOT 3D anaglyph on your film or chip and the stereo base is the distance between the holes. For this little base the system is good only for MACRO3D.
    This is the No-Mir3D method...
    BUT BEFORE STARTING YOU MUST KNOW THESE PARTICULARS TOO!!!!!
    1.The system is good only for long focal lengths, for my opinion from 130-150 mm or higher. I tested it with 160 mm, 360 mm, 480 mm and 720 mm.
    It is independent: the lens is macro or not.
    2. The system works only with NORMAL FOCUS lenses. With RETROFOCUS LENSES; does not work. Usually the compact digital cameras has RETROFOCUS lenses. My Fuji Finepix S7000 fails with the No-Mir3D, it has retrofocus.
    3. The DIAPHRAGMA (aperture) MUST be OPENED AT THE MAXIMUM SIZE, without this the system fails.
    4. The lenses that I tested worked fine with HOLE - DISTANCE about 10-15 mm. Depends from the lens size (diameter) and from the maximum opened diaphragma's size. The size of the holes (diameter) is good when it is 3-5 mm.
    5. Of course WTHOUT FLASH the system does not work. It is good when you have an external good light too.
    6. The system produces FULL FRAME anaglyphs.

    I think it is all for the moment. You can start to try it, I will be very glad to see some results.

    Perhaps a lot of people will have negative opinion and will write the limits of this system. Already now I say: I know well the limits, but show me another similar simple method, for shot macro 3D with only one camera...
    At this time please to see the positive side and possibilities of this method.
    And if you have a little respect for me, so you will use this name:
    No-Mir3D, and I will be very happy!!! Thanks!
    I offer and share the No-Mir3D gladly to all my friends and to all people in the 3D world....I hope will be helpful for a lot of people.......!!!
    I want say another thing.
    The automatic flash, with the max opened diaphragma, works with low light.
    So it is good to use the flash in manual mode (if it is possible) or you
    must use an old classic flash in manual mode...
    Cheers
    Imre
  33. Bens lens is a mirror system for taking anaglyphs in one step and could probably be used in the macro range too - I have not actually heard of this being done. The Guillaume Dargaud method for direct anaglyph photography works on out of focus levels and is an untried technique in the macro range, so far as I know.

*Methods marked with an asterisk allow moving objects to be photographed in 3D.With a bit of messing about, they permit flash. Synchronised flash with two separate cameras is a challenge.

Flash on camera is not perfect when the camera or subject is moved because the shadows are not the same. However, Eric Scanlen uses  method (1) and flash on camera (plus reflectors) for his orchid stereo pictures and they look fine.

How to take 3D photographs

Other links to macro 3D

Electron microscope stereo including snow crystals